[CLIENT][CRASH] League becoming borderline unplayable for me

I'm getting really tired of these connection issues that arose after Kai'Sa came out. League would run flawlessly before then but now it's having a buttload of connection issues right after champ select. Either the little "League of Legends" icon will pop up and nothing happens or I get a black screen and nothing happens OR I get a black screen and a little window that says "failed to connect". This keeps happening to me over and over and over again and I keep getting placed into 20 min leaver buster because of it and I'm so frickin tired of it. My computer and internet are not the problem, they're fairly good and I have no connection issues with any other game, just league.